Epoxy resin-containing ink and process for printing with said inks



United States Patent ABSTRACT OF THE DISCLOSURE A novel printing inkcomposition consisting of a pigment dispersed in a vehicle composed ofan epo'xidized butadiene resin, a dispersed wax, a boron trifluoridemonoethylamine complex in an etherified glycol solvent. The inks areparticularly suitable for printing on glass and metal.-

This invention relates to novel inks containing epoxy resin binderswhich are particularly suitable for printing on glass as well as onmetals.

Inks used in printing on glass articles, such as milk bottles, sodabottles and beer bottles must have the following properties. They mustgive hard printed films, which are abrasion resistant and solventresistant, and they must display excellent adhesion to glass. The lastproperty is relatively rare in inks, since most inks display pooradhesion to glass.

We have discovered a novel epoxy resin containing inks which has all ofthe above properties with respect to glass printing and in addition isvery stable both on the press and during storage. Furthermore, the inkswill not harm the rubber rollers found in most apparatus used inprinting on glass, such as letterpress, lithographic or dry ofisetequipment.

The binder used in the ink of this invention is an epoxy resin havingthe formula:

3,393,167 Patented July 16, 1968 esters could not be used in printinginks since such solvents attack the rubber rollers in the printingequipment. On the other hand, when alcohols and glycols are used assolvents in the inks, the inks exhibit stringiness, undesir- 5 ableadhesion to the rubber rollers causing inadequate distribution as wellas ink flying. Monoalkyl ethers of ethylene glycol are either toovolatile to be used as solvents in the inks of this invention or, asdoes the butyl ether of ethylene glycol, they attack the rubber rollers.0 Likewise, Carbitol type solvents (the alkyl ethers of diethyleneglycol) attack the rubber rollers in the printing equipment.

We have found that methyl and ethyl monoethers of triethylene glycol,dipropylene glycol and tripropylene 1 glycol having either petroleum waxor polyethylene wax dispersed therein make excellent solvents for theepoxy resin-catalyst combination of this invention. These selectedsolvents containing the dispersed waxes do not attack rubber rollers,Neither do inks containing these solvent-wax combinations exhibit anystringiness, un-. desirable adhesion to rubber rollers or flying on thepress. On the other hand, when the wax is eliminated, even inkscontaining these selected monoethers of dipropylene, tripropylene andtriethylene glycol solvents display stringiness, flying and undesirableadhesion to the rubber rollers. This effect of the wax is surprisingsince waxes are not used in printing inks for glass or metal. Inprinting, waxes are primarily used to increase surface slippage ofprinted matter and to decrease tackiness of the ink. However, in thecase of printing on glass or metal, these problems do not exist andconsequently waxes have not been used. Moreover, particularly in thecase of glass with which ink adhesion is quite diflicult to achieve,waxes were generally believed and in many cases found to significantlydecrease the ink adhesion. In the present combination, the wax appearsto have no effect on adhesion. The polyethylene waxes used in thisinvention may be I H H where R is a member selected from the groupconsisting defined as polymers of ethylene with molecular weight therebeing at least one of each member present in the molecule, the n being anumber of such magnitude that the molecular weight of the resin is fromabout 1200 to 1500. The resin is an epoxized polybutadiene and is soldunder the trademark Oxiron. In addition to Oxiron 2000 which has anepoxy percentage of 9%, a hydroxyl percentage of 2.5%, an epoxyequivalent of 177 (number of grams of resin containing 1 equivalent ofepoxide) and an iodine number of 185, Oxiron 2001 having substantiallythe same structure with an epoxy percentage of 11%, a hydroxylpercentage of 2.0%, an epoxy equivalent of 145 and an iodine member of154 may alsobe used. Along with the binder, there is used as catalyst,boron trifluoride monoethylamine complex.

The combination of the selected monoethers of poly glycols and the waxin the vehicle is essential to the practice of this invention. Thestrong solvents conventionally 7 used for coatings containing the Oxironresins such as aromatics and oxygenated solvents such as ketones andbetween 2,000 and 6,000. They are produced by the catalyticpolymerization of ethylene at pressures of 600- 1,000 atmospheres andtemperatures up to 200 C. Most preferable of the polyethylene waxes arethe nonemulsifiable polyethylene waxes having a molecular weight rangeof 2,500 to 3,000.

The petroleum waxes are composed almost entirely of parafiinhydrocarbons. Operable petroleum waxes include paraffin wax, a typicalmixture of which includes paraffins from C H to C I-I andmicrocrystalline wax which includes parafiins from C H- to C H In thepresent specification and claims, all proportions are by weight unlessotherwise set forth. The epoxy resin preferably constitutes from 40 to90%, and most preferably from 50 to of the total vehicle weight. Theboron trifluoride monoethylamine preferably is equal to from 1 to 5% ofthe total vehicle weight While the wax preferably constitutes from 2 to6% of the total vehicle. The remainder of the vehicle weight isconstituted by the solvent. While the solvent may be made up entirely ofthe previously described operable monoethers of polyglycols, if desired,in order to reduce the cost of the inks, volatile aliphatic hydrocarbonsolvents, particularly those 0 having a boiling range of from about 430to 600 F. may

be used as cosolvent. Preferably these cosolvents should not exceed6070% of the total solvent weight.

3 4 Any conventional pigment, e.g., chrome yellow, ultra- EXAMPLE 4marine blue, carbon black and titanium dioxide may be Example 1 isrepeated using e Same procedure used in our inks in the cqnvemional ofgredients, proportions and conditions, except that in place ments ininks h Pigment may constitute fmm 5 of the polyethylene wax, there isused a parafiin wax havto 70% of the mk 5 ing a melting point of 78 C.While we i f with the case of the of thls The resulting printed inkfilms have substantially the invention for printing on glass and metal,these ll'lkS prosame properties as those of Example L vide excellentprinting on other substrates such as paper and lastic sheets andarticles.

Tl i e following examples will illustrate the practice of EXAMPLE 5 thisinvention Example 1 is repeated using the same ingredients, pro- EXAMPLE1 portions, conditions and procedure, except that in Place of a portion(9 parts) of the Dowanol 62B, there is used In avehlcle of the followmgcomposmon' a volatile aliphatic hydrocarbon having a boiling point Partsby weight range of from 375 F. to 475 F. and a K.B. value of 24.

Oxiron 2000 1 50.0 The resulting printed ink films havesubstantially-the Dowanol 62B (the monomethyl ether of tripropylsameproperties as those of Example 1.

ene glycol) 25.8 What is claimed is: V Boron trifluoride monoethylaminecomplex 1.2 1. An ink consisting essentially of pigment dispersed Thefollowing ingredients are dispersed: in a vehicle consisting essentiallyof, (l) a solution in an Polyethylene wax having a molecular weight ofetherified polyglycol solvent selected from the group con- 2,500 to3,000 3.0 sisting of methyl and ethyl monoethers of triethylenePhthalocyanine blue pigment 20.0 glycol, dipropylene glycol andtripropylene glycol of (2) 1 An epoxy resin having the formula OH (I) 0CE CH (i7=O [/0 5H: CH: CH n having a molecular weight of 1,200 to 1,500an epoxy percent of 9.0%, an epoxy equivalent of 177, a hydroxyl percentof 2.5% and an iodine number of 185.

The resulting ink is then used to print upon glass bottles. from 40 to90% by weight of an epoxy resin having the The printed film is cured byheating at 350 F. for 2 formula:

H I R minutes. The printed ink is hard, displays excellent adwhere R--is a member selected from the group conhesion to the glass, excellentsolvent resistance, and abrasisting of sion resistance. The ink is thenused in printing on steel H H sheet metal with the same result. -o\/c-EXAMPLE 2 v 0 and . Example 1 is repeated using the same procedure,ingredients, proportions and conditions except that in place H-H of theDowanol 62B, there are respectively used: monomethyl ether oftriethylene glycol, the monoethyl ether of at ast ne Of R beingtripropylene glycol and the monomethyl ether of dipropyl- 65 H H eneglycol, the results are substantially the same as those of Example 1 ineach case.

EXAMPLE 3 and at least one R=being Example 1 is repeated using the sameprocedure, ing gredients, proportions and conditions, except that inplace of the polyethylene wax there is used a microcrystalline and n isa number of such magnitude that the average wax having amelting point of194 F. molecular weight of the rain is from 1,200 to 1,500, (3)

The resulting printing has substantially the same propfrom 2-6% byweight of a dispersed wax selected from erties as that of Example 1. thegroup consisting of petroleum waxes and polyethylene wax and (4) from1-5% by weight of boron trifiuoride monoethylamine complex.

2. The ink of claim 1 wherein said epoxy resin has an epoxy equivalentof 177 and an average molecular weight of about 1,200.

3. The ink of claim 1 wherein said wax is polyethylene wax having amolecular weight of from 2,500 to 3,000.

4. The ink of claim 1 wherein said wax is microcrystalline Wax.

5. The ink of claim 1 wherein said wax is paraffin wax.

6. The ink of claim 1 wherein said solvent is monomethyl ether oftripropylene glycol.

7. The ink of claim 1 wherein said solvent is the monoethyl ether oftripropylene glycol.

8. The ink of claim 1 wherein said solvent is the mono- 15 ethyl etherof triethylene glycol.

9. The ink of claim 1 wherein said solvent is the monomethyl ether ofdipropylene glycol.

10. The ink of claim 1 where said solution further includes a volatilealiphatic hydrocarbon cosolvent. 90

6 where R is a member selected from the group consisting of H H -o\-/oand H H .C=C

at least one of R being H H C\ o and at least one R being and n is anumber of such magnitude that the average molecular weight of the resinis from 1,200 to 1,500, (3) from 2-6% by weight of a dispersed waxselected from the group consisting of petroleum waxes and polyethylenewax, and from 1-5% by weight of boron trifiuoride monoethylamine complexand then heating said printed substrate to cure the ink.

H O CH CH l $=O O CH1 CH: CH: [1

Where n is a number of such magnitude that the average molecular weightof the resin is about 1,200, the resin having an epoxy equivalent of 177and an iodine number of 185 from 26% by weight of, a dispersedpolyethylene wax having a molecular weight of 2,500 to 3,000 and from15% by weight of boron trifiuoride monoethylamine complex.

13. A process for printing on a substrate selected from the groupconsisting of glass and metal 'which comprises printing on saidsubstrate with an ink consisting essentially of pigment dispersed in avehicle consisting essentially of a solution in the 'monomethyl ether oftripropylene glycol of from 40-90% by weight by an epoxy resin havingthe formula 12. A process for printing on a substrate selected from thegroup consisting of glass and metal which comprises printing on saidsubstrate with an ink consisting essentially of a pigment dispersed in avehicle consisting essentially of a 1) solution in an etherifiedpolyglycol solvent selected from the group consisting of methyl andethyl monoethers of triethylene glycol, dipropylene glycol and 0tripropylene glycol of (2) from 40-90% by weight of an epoxy resinhaving the formula:

0 E I H 0 CH3 OH: H

where n is a number of such magnitude that the average molecular weightof the resin is about 1,200, the resin having an epoxy equivalent of 177and an iodine number of 185, from 26% by weight of a dispersedpolyethylene wax having a molecular weight of 2,500 to 3,000 and from1-5% by weight of boron trifiuoride monoethylamine complex and thenheating said printed substrate to cure the ink.

LO i 5 n it References Cited UNITED STATES PATENTS MORRIS LIEBMAN,Primary Examiner.

B. AMERNICK, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,393,167 July 16, 1968 Frederick A. Varron et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, line 5, "InternationalCorporation" should read Interchemical Corporatlon Column 6, line 36,"by", second occurrence,

should read of Signed and sealed this 24th day of February 1970.

(SEAL) Attest:

"Eiivrd M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents

